Mercury is a very chemically toxic metal that has been proven to cause developmental disorders in children, as described by the EPA here:
EPA America’s Children and the Environment: Neurodevelopmental Disorders | Third Edition, Updated October 2015 https://www.epa.gov/sites/production/files/2015-10/documents/ace3_neurodevelopmental.pdf
Lead, methylmercury, and PCBs are widespread environmental contaminants associated with adverse effects on a child’s developing brain and nervous system in multiple studies....
EPA has determined that methylmercury is known to have neurotoxic and developmental effects in humans.23 Extreme cases of such effects were seen in people prenatally exposed during two high-dose mercury poisoning events in Japan and Iraq, who experienced severe adverse health effects such as cerebral palsy, mental retardation, deafness, and blindness.24-26
Prospective cohort studies have been conducted in island populations where frequent fish consumption leads to methylmercury exposure in pregnant women at levels much lower than in the poisoning incidents but much greater than those typically observed in the United States.
Results from such studies in New Zealand and the Faroe Islands suggest that increased prenatal mercury exposure due to maternal fish consumption was associated with adverse effects on intelligence and decreased functioning in the areas of language, attention, and memory.26-32 These associations were not seen in initial results reported from a similar study in the Seychelles Islands.33 However, further studies in the Seychelles found associations between prenatal mercury exposure and some neurodevelopmental deficits after researchers had accounted for the developmental benefits of fish consumption.34-36
More recent studies conducted in the United States have found associations between neurodevelopmental effects and blood mercury levels within the range typical for U.S. women, after accounting for the beneficial effects of fish consumption during pregnancy.32,37,38Given the amount of evidence accumulated documenting the dangers of mercury for children, I do not understanding why the EPA is withdrawing mercury protection rules:
Anne Hawke and Elizabeth Heyd. 2/1/207. NRDC Sues EPA Over Withdrawal of Mercury Protection Rule. National Resource Defense Council, February 01, 2017 https://www.nrdc.org/media/2017/170201
NEW YORK – The Natural Resources Defense Council today sued the Environmental Protection Agency for illegally rescinding a rule that would protect the public from more than five tons of mercury discharges each year.
In a lawsuit filed in U.S. District Court here, NRDC said EPA broke the law by withdrawing the mercury protection rule without public notice or an opportunity for comment. The White House ordered agencies to withdraw a broad array of rules issued by the Obama Administration to protect public health and the environment.
In its complaint, NRDC contends EPA cannot withdraw the mercury protection rule based on the Trump Administration’s fiat because the rule is final. EPA issued the rule in December to limit substantially the amount of mercury dental offices across the nation discharge regularly.